The flow of energy can be traced in the following order:
- Step 4 - The sun emits energy.
- Step 5 - Plants absorb energy from the sun and use it for photosynthesis.
- Step 3 - A rabbit eats the plants and uses the energy for growth and respiration.
- Step 1 - A fox eats the rabbit and uses the energy for growth and respiration.
- Step 2 - The fox dies and is decomposed.
So the correct order is: 4, 5, 3, 1, 2.